There are many cases where even republicans go on record stating man made climate change. It is basicly the Oil industry who is trying to keep the doubt about it. So the politicians Democrat or republican (mostly republican) who come from the Energy Producing states. Will play onto the spew to keep themselves elected.
Politics are not Pro- or Anti-Science. It is weather the science is political useful for them or not. Otherwise they will be happy putting their head in the sand.
Have you ever visited a coal mining town that doesn't mine coal anymore? The end result is almost always a severely depressed area, rampant poverty, high unemployment and underemployment, high drug use and abuse, prostitution, etc. A lot (millions) of people live in oil towns and oil cities in the US. For the good of the world, maybe we need to cut back on oil and gas. But the politicians would not be doing their job if they didn't represent the people who elected them.
I see a lot of people calling for an end to oil and gas but nobody ever makes a plan, or offers to fund a plan, on how to retrain all the workers, repurpose the assets, align interconnected industries, etc. It hasn't been done because the problem is a lot more difficult than environmentalists ever imagine.